The present invention relates to a misconnection-proof key and a connector having a plurality of contacts using a plurality of the misconnection-proof keys for preventing the connector from being connected to an improper mating connector.
To date, attempts have been made to prevent misconnection of connectors. One attempt is to make the front end of the metal shell of a connector in the form of a trapezoid in cross-section instead of a rectangle, thereby preventing the connector positioned upside down from being connected to a mating connector. In order to connect a connector to a predetermined mating connector only, in another attempt, the connector is provided with a U-shaped key of plastics fitted in the predetermined end of the metal shell of the connector, so that the predetermined mating connector can be selected by ascertaining whether the mating connector has a notch at a predetermined position for receiving the U-shaped key.
However, such a U-shaped key of plastics is likely to be broken when strong force is temporarily applied thereonto, and is likely to shift its position when a mating connector is being removed from the connector, whereby its performance for preventing misconnection would be lost. Such a fault would be caused by the fact that the U-shaped key is made of plastics and that it does not have means for anchoring it at its predetermined position.